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Unformatted text preview: MasteringPhysics: Course Home Student View 2/22/11 9:04 AM Summary View Diagnostics View Print View withEdit Assignment Answers Settings per Student Introduction to MasteringPhysics Due: 12:00pm on Thursday, January 27, 2011 [ Print ] Note: You will receive no credit for late submissions. To learn more, read your instructor's Grading Policy The purpose of the following exercises is to familiarize you with the system you will be using for the rest of your course. These exercises are not intended to teach or test your knowledge of any specific subject material. Therefore, you will not be penalized for using hints or submitting incorrect answers. Welcome! Description: This exercise introduces students to the Mastering program. This introduction includes the typical item format and grading scheme. Mastering presents homework items assigned by your instructor and works with you to answer them. Homework items typically have an introduction, possibly figures, and one or more parts for you to answer. Type of help offered Mastering tells you immediately whether or not your answers are correct. Usually, you will have multiple chances to arrive at the correct answer. Your instructor will determine how many tries you have available. In many items, hints are available to help you if you get stuck. If you don't need the hints to solve the problem, you can still use them for review later on. If you submit an incorrect answer, Mastering often responds with specific, helpful feedback. Mastering is forgiving of many typos and formatting mistakes. If it can't figure out what you entered, it will let you know and give you another chance. These exercises were chosen specifically to lead you through the key features of Mastering and are not intended to test your knowledge of any specific subject material. Therefore, on this item you will not be penalized for using hints and submitting incorrect answers. In fact, you should submit incorrect answers and use the hints to see what happens! Part A How many squares are in this grid ? Note that the figure link lets you know that a figure goes along with this part. This figure is available to the left. Enter your answer as a number in the box below and then submit your answer by clicking Submit. http://session.masteringphysics.com/myct/courseHome Page 1 of 17 MasteringPhysics: Course Home ANSWER: 2/22/11 9:04 AM 5 Number of squares = 5.00 5.0 What you are reading now is called a "follow- up comment." These comments typically offer more information or provide an interpretation of the answer you just obtained. Before you move on to a slightly more challenging question, have a quick look at the other buttons available around the answer box. Show Answer gives you the answer to the question if you can't figure it out on your own. Your instructor controls whether or not this button is available. If it is not available, you will see the Give Up button instead. My Answers brings up a new window that lists all of the answers you have submitted for this question, along with any helpful feedback you received for incorrect submissions. Grading See the help file available by clicking the Help tab in the top right corner, if you want to know more about how grading works. Here is the most important information you'll need. In a graded homework item, each part counts equally toward your score on the overall item. If you get full credit on each part, you will receive full credit for the problem. You may lose a fraction of the credit for a part when you submit an incorrect answer. Whether you do lose credit and how much you lose are set by your instructor. However, you won't lose credit for most types of formatting mistakes or for submitting a blank answer. As you might expect, you will receive no credit if you use the Show Answer button. If you just can't figure out a question, there is a way to get partial credit by using hints, as the following part will illustrate. Part B What is the magic number ? Note that there is a figure also associated with this part. However, the figure for Part A may still be visible on the left. To view the figure associated with Part B, click on the figure link. A new figure should appear on the left. Hint B.1 Different types of hints and their impact on grading Notice that there are three hints for this question. You are not required to use all of the hints or to use http://session.masteringphysics.com/myct/courseHome Page 2 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM them in order. Each hint has a tagline that describes its contents. Based on the tagline you can decide whether or not a particular hint will be useful to you. There are two kinds of hints. Some hints, such as Hint 2 below, just provide you with information. Other hints, such as Hint 3 below, give you an opportunity to answer a simpler question that is related to the main question you are solving. These hints either have questions in the tagline or tell you to do something (e.g., Find..., Determine..., Identify..., etc.). There are two ways that this type of hint can help you: Answering the simpler question gives you a chance to check that you are on the right track. If you correctly answer the simpler question, you will receive partial credit for the part even if you are unable to answer the main question. Your instructor may choose to give you a bonus for not using hints or to deduct a small penalty for using hints. If you are stuck, using the hints will usually result in a higher score than simply trying to guess because you may lose fewer points for opening a hint than for getting the answer to the main question incorrect. There is a more detailed explanation of how hints are graded in the help available by clicking the Help tab in the top right corner of your screen in the main Mastering window. In this problem, however, you will not lose any credit for using the hints. Now, open up the second hint for some help finding the magic number. Hint B.2 How to approach the problem Although you could try to guess the magic number you would most likely exhaust your tries before getting the correct answer. To help you, the magic number is , where is a number between 1 and 10. Hint B.3 What is ? Recall that the previous hint stated that the magic number is and 10. Specifically , where is a number between 1 is an even number between 1 and 10. Try to guess the value of . You may submit as many guesses as you need. Enter each guess into the answer box that follows. ANSWER: =4 Now that you have determined , compute to find the magic number. You could try to guess the magic number but you would probably use up all your tries before getting the answer. Notice the new H ints button underneath the answer box for this question. Clicking this button will open up a list of hints that will guide you to the correct number. ANSWER: magic number = 60 Your instructor may choose to give you a bonus for not using hints or to deduct a small penalty for using hints. If you are stuck, using the hints will usually result in a higher score than simply trying to guess because you may lose fewer points for opening a hint than for getting the answer to the main question incorrect. Note that you are never required to use the hints; if you want to figure the question out on your own, go ahead! Notice that a new button, Review Part , appears when you correctly answer a part with hints. This http://session.masteringphysics.com/myct/courseHome Page 3 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM button allows you to review all of the hints for that part, even if you didn't need them to get the answer. This is a useful way to review the question when studying for a test. You do not lose any credit for reviewing the hints after you have answered the question. If you didn't look at all of the hints while answering the last question, you should read through them now for some important information about hints and hint grading. Part C Multiple- choice questions have a special grading rule determined by your instructor. Assume that your instructor has decided to grade these questions in the following way: If you submit an incorrect answer to a multiple- choice question with options, you will lose of the credit for that question. Just like the similar multiple- choice penalty on most standardized tests, this rule is necessary to prevent random guessing. If a multiple- choice question has five answer choices and you submit one wrong answer before getting the question correct, how much credit will you lose for that part of the question ? ANSWER: 100 50 33 25 20 Your instructor may choose not to deduct of the credit for a multiple- choice question with options. To see how your instructor is grading you, click your instructor's Grading Policy on your assignment page. If you click on the Continue button or the See Score link before finishing all the Parts, you will see a message reminding you that you need to complete each Part to get credit or see your score. If you have completed the item, clicking Continue will take you to the next item on the Assignment whereas clicking on the See Score link will take you to your score summary and survey page. Introduction to Numeric Answers Description: Students are introduced to the math answer box used to enter numeric answers. The problem describes how most numeric questions are graded based on tolerance. This exercise is not intended to test your knowledge of any specific subject material. Therefore, on this problem you will not be penalized for using hints or submitting incorrect answers. Overview When an assignment question requires that you enter a numeric answer, you will see an answer box like the one illustrated here. http://session.masteringphysics.com/myct/courseHome Page 4 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM To answer this type of question, you will need to type the numeric value for distance in the rectangle between the quantity you are solving for (distance) and the units (meters). In addition to typing alphanumeric values from your keyboard, you can enter non- numeric information by using either the menu tabs above the rectangular answer box (for more information click Help ) or the equivalent key strokes, as listed in the Shortcuts menu. Grading Tolerance For grading, your numeric answers often (but not always) can be within a tolerance range of the official answer. For example, if the answer to a numeric problem with a tolerance of 2% were 105, answers between 103 and 107 would be graded as correct. If you submit an acceptable but not totally accurate answer, the official correct answer will also be displayed in a purple feedback box so that you can use it in later calculations if needed. Using this same example, you will see a message in a purple box advising you to use 105 in any further calculations that may be based on this answer. Significant figures Most questions with numeric answers will require your answer to be given to at least three digits or significant figures. Your answer may be graded as incorrect if you have calculated correctly but then rounded your final answer to too few digits. If a different number of significant figures is required, this will be part of the question's answer instructions. When you need to do multiple calculations to get an answer, use more significant figures than required in each calculation and round at the end only. Rounding too early can cause your final answer to be outside the tolerance range. Part A For most answers, you will simply enter your numeric answer directly into the space provided to the right of the equal sign. Answer the following question by typing the numeric answer into the answer box. If you have a gross of items, you have 144 items. If you buy a gross of eggs, how many dozen eggs do you have ? Hint A.1 How many items are in a dozen ? If you have a dozen items, how many items do you have ? ANSWER: 6 items 12 items 13 items A dozen contains 12 items and a gross contains 144 items. To find out how many dozen are in a gross, you need to determine how many times 12 goes into 144. http://session.masteringphysics.com/myct/courseHome Page 5 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM Express your answer in dozens. Do not enter the units; they are provided to the right of the answer box. ANSWER: number of eggs = Part B When entering large numbers in the answer box, do not use commas. For example, enter 1276400 for the number 1,276,400. Do not enter 1,276,400. If you accidentally enter commas, you will get a message that your answer has the wrong number of terms. Answer the following question by typing the numeric answer into the answer box. What is the sum of 9260 and 3240? Hint B.1 How to compute the sum Recall that the sum of two numbers is the result you obtain by adding the two numbers together. Express your answer numerically to at least three significant figures. ANSWER: sum = Note that you can always review exactly what you typed in the answer box by clicking My Answers . Scientific notation You may want to enter 367,000,000 in scientific notation as Instead of the . symbol, use a multiplication dot ( ) by typing the keyboard multiplication symbol * (Shift + 8). To input the exponent for numbers written in scientific notation, do either of the following: Click the button found under the menu. Type ^ (Shift + 6) from your keyboard. For example, can be entered in the answer box by typing 3.67*10^8. Part C Practice entering numbers in scientific notation by entering the diameter of a hydrogen atom in its ground state, , into the answer box. Express the diameter of a ground- state hydrogen atom in meters using scientific notation. Do not enter the units; they are provided to the right of the answer box. ANSWER: = http://session.masteringphysics.com/myct/courseHome Page 6 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM In some computer programming languages and software, a shorthand scientific notation for a number such as would be 3.0E12. This notation should be avoided when using the math answer box, because the E will be interpreted as a variable. To correctly enter as an answer, follow the advice given above. Part D If you are asked to provide a set of two or more numeric answers, separate them with commas. For example, to provide the year that Sputnik (the first satellite to be sent into orbit around the Earth) was launched and the year humans first walked on the Moon, you would enter 1957,1969 in the answer box. A rectangle has a length of 5.50 and a width of 12.0 . What are the perimeter and area of this rectangle ? Hint D.1 How to find the perimeter The perimeter of a two - dimensional shape is the distance around the outside edge of the shape. In the case of a rectangle, there are two sides of length and two sides of width . Therefore, if you were to walk around the outside of a rectangle, you would walk a distance of Hint D.2 The area or . How to find the area of a rectangle is given by the product of its length and width : . Enter the perimeter and area numerically separated by a comma. The perimeter should be given in meters and the area in square meters. Do not enter the units; they are provided to the right of the answer box. ANSWER: perimeter, area = , Introduction to Symbolic Answers Description: Students are introduced to using the math answer box to enter symbolic answers, including variables and Greek symbols. This exercise is not intended to test your knowledge of any specific subject material. Therefore, on this problem you will not be penalized for submitting incorrect answers. Overview The type of answer box illustrated here lets you build a symbolic expression just as it would look in your textbook or as you might write it by hand. http://session.masteringphysics.com/myct/courseHome Page 7 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM You use the same answer box and menu tabs to enter numeric and symbolic answers. To insert a formatting template , such as an exponent, square root, or fraction, click select the appropriate template. To insert lowercase Greek letters and To insert uppercase Greek letters and To undo your work , click (hbar), click To clear your work (restart) , click and then select the letter you want. (EMF) , click . To redo your work , click and then and then select the letter you want. . . To view a list of keyboard shortcuts , click . Here are some of the most common shortcuts: Subscript: Type _ (an underscore). Exponent: Type ^ (Shift + 6). Fraction: Type / (a forward slash). Square root: Type \sqrt. Greek letters: Type a backslash ( \) and the name of the Greek character. For example, to display , you would type \delta. For uppercase Greek letters, begin the name with a capital letter. For example, you would type \Delta to display . For more information , click ( ). To identify the purpose of any icon, simply place your cursor over it. For instance, here is an example showing the Greek letter Omega: . Grading Your answers are graded according to the standard order - of- operations conventions for evaluating mathematical expressions, as follows: Perform any calculations inside parentheses. Perform all multiplications and divisions, working from left to right. Perform all additions and subtractions, working from left to right. For example, in the expression , first you should multiply by and then add to the total. In other words, the correct expression is . Part A Similar to what you see in your textbook, you can generally omit the multiplication symbol as you answer questions online, except when the symbol is needed to make your meaning clear. For example, is not the same as . When you need to be explicit, type * (Shift + 8) to insert the multiplication operator. You will see a multiplication dot ( ) appear in the answer box. Do not use the symbol the expression , typing m Enter the expression . For example, for a would be correct, but mxa would be incorrect. . http://session.masteringphysics.com/myct/courseHome Page 8 of 17 MasteringPhysics: Course Home ANSWER: 2/22/11 9:04 AM = When entering algebraic expressions, such as ma , you can enter it using explicit multiplication m a or implied multiplication ma. Both will be accepted as correct. Part B Enter the expression , where is the lowercase Greek letter theta. ANSWER: = To identify a variable displayed in a specific part, place your cursor over it. For instance, here is an example showing the Greek letter theta used in this problem: . Part C Enter the expression , where ANSWER: is the inverse sine function. = Use the same notation to enter other inverse trigonometric functions, for example and for the inverse cosine and tangent functions respectively. Part D Enter the expression , where is the uppercase Greek letter Delta. ANSWER: = http://session.masteringphysics.com/myct/courseHome Page 9 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM Part E Enter the expression , where is N - naught (an N with a subscript zero) and is the lowercase Greek letter lambda. ANSWER: = Introduction to Sorting Questions Description: This exercise introduces students to using the sorting answer type. This exercise is not intended to test your knowledge of any specific subject material. Therefore, on this question you will not be penalized for using the hint or submitting incorrect answers. Overview Sorting questions require you to place objects into different categories or bins. There will always be at least two bins and each bin is labeled according to the category it represents. An object can only belong to one bin. A bin can remain empty. Before an answer is submitted, it is possible to rearrange the objects by dragging them to new locations. To start over, click Reset . Once you're satisfied with your sorting, click Submit . Part A Correctly classify the given food items as either a fruit or a vegetable. If you need help, look at the hint available by clicking Hints . Hint A.1 How to distinguish fruits from vegetables Botanically speaking, anything that grows from a flower and bears seeds is considered a fruit. For example, oranges, grapes, and strawberries are all fruits. True vegetables are those that come from a part of the plant that is not the flower, such as leaves, stems, and roots. Thus lettuce, cabbage, and radishes are all vegetables. Drag the foods into the appropiate bins. Fruits should be placed in the left bin. Vegetables should be placed in the right bin. ANSWER: http://session.masteringphysics.com/myct/courseHome Page 10 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM View A tomato comes from a flower and contains seeds, so it is a fruit and is classified as a berry. An avocado contains a large seed in its center similar to peaches, apricots, and mangos. Plants such as cucumbers, squash, green beans, peppers, and eggplants are also fruits by this definition, although they are usually used as vegetables in cooking. Keep in mind that you can refer to this question or consult the Help if you have difficulty using this answer type later on. Introduction to Ranking Questions Description: This exercise introduces students to using the ranking answer type. This exercise is not intended to test your knowledge of any specific subject material. Therefore, on this question you will not be penalized for submitting incorrect answers. Overview Rankings are usually ordered from left to right. Check the problem instructions to be sure. To rank two (or more) objects that are equivalent, drag one object into the ranking bin then drag the second object to overlap it. These objects will then automatically align to be slightly offset (so you can see both of them at once). You will know they are equal because a vertical gray bar will appear behind them to indicate an equivalent ranking group. Sometimes, it will be impossible to rank the objects based on the information given. In such a case, click on the box labeled "The correct ranking cannot be determined" below the ranking window. Before an answer is submitted, it is possible to rearrange the objects by dragging them to new locations. To start over, click Reset . Once you're satisfied with your ranking, click Submit. Part A Each of these geometric shapes has a different number of sides. Arrange the shapes in order from the shape with the greatest number of sides to the shape with the fewest number of sides. Rank these shapes from greatest to fewest number of sides. To rank items as equivalent, overlap them. ANSWER: View Note that when two or more objects are equivalent they are placed one atop another. They will appear slightly offset, but the background color behind them will change to light gray to indicate that http://session.masteringphysics.com/myct/courseHome Page 11 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM the items are in the same equivalent ranking group. Keep in mind that you can refer to this question or consult the Help if you have difficulty using this answer type later on. Introduction to Graphing Questions Description: This exercise introduces students to creating graphs using the graphing answer type. This exercise is not intended to test your knowledge of any specific subject material. Therefore, on this question you will not be penalized for submitting incorrect answers. Overview When an assignment question requires that you answer by plotting a graph, you will see the following buttons: To add a new graph , click . You will first be prompted to select a label. Then you can add points. (After adding your first point, the tool automatically changes to add points mode.) You can create as many "unlabeled graphs" as you like - - these will not be graded. To add or edit points on a graph , select these two modes. About adding points: Your cursor appears as a crosshair with or . This button toggles between coordinates next to it. To add a point, click a location. To add multiple points at a time, click and drag your mouse. About editing a graph: Using a mouse : To move a point, click to select the point and then drag it to the new location. To move the entire graph to a new location, click between points on the graph and then drag. Using your keyboard : With a point or graph selected, press any arrow key to reposition. About selecting/deselecting points and graphs : Click on any point to select it. To select a graph, click between points. Actively selected points and graphs are highlighted. To deselect a point or graph, click an empty area of the workspace. To delete a selected point or graph , click or . To delete using your keyboard, press Delete or Backspace after selecting a point or selecting a graph. To change the graph label for the active graph , click . To reset your graphs to the most recently submitted answer (restart) , click For help with graphing, click . . Part A Create a graph of Hint A.1 . Identify a point to graph You need to create a plot of . To identify points on this graph you must solve for the values of http://session.masteringphysics.com/myct/courseHome when takes on different values. Page 12 of 17 MasteringPhysics: Course Home What is 2/22/11 9:04 AM when ? Express your answer numerically. ANSWER: 4 4.0 4.00 Now, to create your graph, find at least one other pair of Construct a graph corresponding to the linear equation and values to plot. . ANSWER: View Now that you have some experience with graphing task question types you can tackle harder graphs. Introduction to Vector Drawing Questions Description: This exercise introduces students to vector drawing questions. When an assignment question requires that you answer by drawing vectors, you will see the following buttons. To draw a new vector , click and select the label for the vector that you want to draw. You can draw the vector by clicking on the start point and dragging your mouse to the end point. To edit an existing vector , click to select either the vector, its start point, or its end point. Drag the selected vector or point to a new location. To deselect a vector or point, click on any empty area of the workspace. To view the sum of all the vectors in your drawing, click every problem. To delete a selected vector , click Backspace after selecting a vector. . To delete using your keyboard, press Delete or To change a label or get information about a vector , click such as the following: http://session.masteringphysics.com/myct/courseHome . This option is not available in to display a properties window Page 13 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM Change a label by selecting another. Vector properties (Start point, End point, Length or Angle) will display, if they are required for you to complete the drawing. To reset your vectors to the most recently submitted answer (restart) , click For help with drawing vectors, click . . Part A Every morning Ann walks her dog through the park, shown as a green square on the diagram below. They start at point 1, walk one block up the street, take a turn at the corner labeled 2, and walk diagonally through the park to point 3. To return home, they walk two blocks down the street and turn right at the corner labeled 4. Draw the path taken by Ann as she walks her dog. Represent each segment of Anna's walk with a vector. The vectors should start and end at the centers of the red dots located on the image. ANSWER: View Besides drawing vectors by connecting two given dots, you will often have to draw vectors of a given length or at a specific angle. In these cases, click and read the information you need from the properties window as you adjust your vector to the desired length or angle. Part B Now imagine that instead of walking along the path straight line , Ann walks 80 meters on a north of east starting at point 1. Draw Ann's path. Represent Ann's walk with a vector of length 80 meters. Draw the vector starting at point 1. The length displayed in the Vector Info properties window is given in meters. ANSWER: http://session.masteringphysics.com/myct/courseHome Page 14 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM View You can use the button to adjust the start point, end point, length, and orientation of a vector: Click on the button to display the properties window. Drag the properties window to a location where it will not prevent you from seeing and manipulating the vector. Draw the vector at the desired location. As you draw the vector, notice the information displayed in the properties window (start point, end point, length, and angle). Depending on the question, some information may not be available in the properties window. When an angle is displayed, it is the angle, measured counterclockwise, that the vector makes with respect to the positive axis pointing toward the right (east). Adjust the vector until the desired start point, end point, length, and angle are displayed in the properties window. Reviewing the Fundamentals Description: This exercise reviews the key points of Mastering for students. Ideally students will finish the assignment excited about Mastering's potential to help them learn. Try this final item to review some of the key concepts you've learned. Part A You are starting a new item and after reading the first part you realize you have no idea how to go about answering it. What should you do ? ANSWER: Use the available hints. Guess randomly and hope for some useful feedback. Request the solution immediately. The hints are designed for exactly this reason: to give you something to work with if you are absolutely stuck. You will most likely score higher (and learn more!) if you use the hints when you need them rather than guessing or giving up. Part B You have been working on an item for a while and after a few missteps you've come up with an answer. However, there is one particular thing that you're not 100 sure of. What should you do ? Select all that apply. http://session.masteringphysics.com/myct/courseHome Page 15 of 17 MasteringPhysics: Course Home ANSWER: 2/22/11 9:04 AM Submit your answer and then adjust it according to any feedback you receive. Check for any hints that address the part of the calculation you're unsure about. Return to the question after you've spoken with an instructor or classmate. None of the above. There is no single right way to proceed if you've made some progress on an item but are not 100 sure of your work. If you submit the answer, you might be right and there is a good chance you will get some useful feedback. There is also a good chance that the hints address whatever issue you are unsure about. Finally, if your instructor allows it, talking over your solution with someone else could be a good way to go.You should do whatever you find works best for you. Part C You've just solved a problem and the answer is the mass of an electron, . How would you enter this number into the answer box? Hint C.1 Multiplication and superscripts Type the following: 9.11*10^-31. The keyboard multiplication symbol * (Shift + 8) will appear as a multiplication dot, and the carat symbol ^ (Shift + 6) will superscript the line. Another way to get an exponent is by clicking menu. in the Enter your answer in kilograms using three significant figures. Note that the units are provided for you to the right of the answer box. ANSWER: = Part D A friend in your class tells you that she never uses hints when doing her Mastering homework. She says that she finds the hints helpful, but when the hint asks another question it increases the chance that her score on the problem will go down. She feels like it isn't worth the risk.You reassure her that there is nothing to fear about opening a hint that asks a question. Which of the following are good reasons for your friend not to worry? Select all that apply. ANSWER: As an incentive for thinking hard about the problem, your instructor may choose to apply a small hint penalty, but this penalty is the same whether the hint simply gives information or asks another question. The only way to lose additional partial credit on a hint is by using the "show answer" button or entering incorrect answers. Leaving the question blank will http://session.masteringphysics.com/myct/courseHome Page 16 of 17 MasteringPhysics: Course Home 2/22/11 9:04 AM not cost you any credit. Getting the correct answer to the question in a hint actually gives you some partial credit, even if you still can't answer the original question. None of the above. That's it! You're done! We hope you enjoy using Mastering. Score Summary: Your score on this assignment is 0%. You received 0 out of a possible total of 8 points. http://session.masteringphysics.com/myct/courseHome Page 17 of 17 ...
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